Oil well tool



COPY

P. H. GRANG Aug. 1'7, 1943.

O IL WELL TOOL 2 Sheets-Sheet 1 Filed March l5, 1941 Aug. 17,1943. 1 P1 H. GRANGER *2,326,940

OIL WELL TOOL Fned March 15, 1941 2 sheets-sheet 2 Suma/hm .PAUL GRANGE/e,

Patented Aug. 17, 1.943

UNITED STATES PATENT OFFICE OIL WELL TOOL Paul H. Granger, Los Angeles, Calif.

Application March 15, 1941, Serial No. 383,589

11 Claimsn (Cl. 16S-11) This invention relates generally to oil well tools and, more particularly to a tool which may be used for locating leaks yin well casings, cementing such leaks, testing'formations, or for other operations where it is desirable to establish fluid communication between a string of tubing and a localized portion of/ a well casing.

Tools of this type are suspended from the tubing string and are provided with an internal passage aiiording communication between the tubing string and a localized zone in the casing around the tool, which zone is sealed off by vertically spaced packers carried by the tool from the spaces in the casing above and below the packers. The packing means seal tightly with the inner face of the casing and means are provided for by-passing fluids past the packing means, between the interior of the casing above ,and below the packing means, when the tool is moved vertically in the casing. It is particularly desirable to provide means for closing the bypass passage when the tool is in operating position in order to carry out certain operations which will be described.

`In operations attendant to locating leaks in the casing, cementing them, and ushing the tool, tubing and casing after the cementing is accomplished, or in other operations tor which such tools are used, it is desirable to provide for the establishment of liquid iiow through the tubing, casing or tool in various ways depending upon the particular situation. For example, in leak locating and cementing operations it is desirable to establish iiow between the tubing string and only the localized zone in the casing. According to one flushing loperation that is practiced, it is desirable to establish a reversed flow in the tubing and casing by forcing liquid down in the casing past, the upper packing means and into the localized zone, and thence lupwardly through the tubing. 'I'his operation requires that there be no communication through the tool between the localized zone in the casing and the interior of the casing below the lowermost packing means. According to another flushing procedure, it is desirable to force liquid down the tubing string and flush the interior of the tool into the interior of the casing below the lowermost packing means, this last procedure requiring a passage between the passage inside the tool and the interior of the casing below the lowermost packing means It is an important object of this invention to provide a tool of the class described ladapted to establish liquid ilow between the localized Zone in the casing and the interior of the casing below the packing means and provided with valve means controllable from the surface to regulate the liquid flow whereby the tool is adapted to both of the above-mentioned ushing procedures and is also adapted to drain the tubing string as the tool is moved upwardly out of the casing.

It is a further object of the invention to provide a tool of the class described having a bypass passage establishing liquid flow between the casing spaces above and below the packing means in order to permit ready vertical movement of the tool in the casing, and having valve means controlling liquid Ilow in the by-pass, which may be closed automatically by liquid pressure when the tool is flushed by reversed circulation as above described.

Another object of the invention is to provide a tool-of the class described havinga by-pass passage for well liquid and pressure-operated valve means for the passage which is adapted to be automatically opened by fluid pressure when the tool moves down in the casing and which is positively opened by upward movement of the tool with respect to the casing, the valve means being open when the tool is in motion up or down.

A further object of my invention ia. to provide a tool of the class described with a main vertical passage and valve means regulating liquid ow through the passage, the valve means being automatically opened by upward movement of the tool with respect to the casing whereby liquid in the tubing string is automatically drained back into the well as the tubing is removed from the Well.

It is a further object of the invention to provide a simple, effective, rugged and easily maintained apparatus for establishing fluid communication with a localized zone of the well casing.

Further objects and advantages of the invention will eithercbe specically brought out in the ensuing description or will become apparent therefrom.

My invention will be better understood from the ensuing description taken in connection with the accompanying drawings, in which:

Fig. 1 is a vertical section of a preferred form of my tool showing it in place in the casing;

Fig. 2 is a fragmentary vertical section of the lower portion thereof showing the valve-operating mechanism in valve-opening position;

l Fig. 3 is a sectional detail taken along line 3-3 in Fig. 1';

Fig. 4 is a fragmentary section and elevation taken along line 4-4 in Fig. 2; and

Fig. 5 is a fragmentary vertical section of a modied form of tool,

Referring to Figs. 1 to 3 of the drawings, and particularly to Fig. 1, the tool is shown as comprising a vertically elongated body member `-`I preferably cylindrical, provided with a reducing coupling 2, to which it is threadedly secured atits upper end, for threadedlyreceiving the lower end of tubing string 3 from which the tool is suspended. The tool is further provided v2 v a 2,326,940

with'vertically spaced packing means, auch as upper and lower packers 4 and l of rubber or the like, packers l and 5 face inwardly toward one another and are adapted to sealingly engage the inner face of the casing indicated at 8 to seal off between them a localized zone 1 around body I and inside the casing, this zone being cut of! from fluid flow with the spaces in the casing above and below the packers. It is also within the scope of my invention to use four packers on the tool, adding an outwardly facing packer above and below each oi packers 4 and 5, asis used in leak-locating tools.

'Ihe packers may be secured to the tool in any suitable manner. For example, the lowermost packer 5 may be held -between a ring 8 secured to the body I as by welding and a conical metal follower 8 which is forced against the packer by pressure transmitted from a nut threaded to the body. A suitable washer I2 may be provided between the nut II and the follower 8. The upper packer 4 is shown held in place by similar construction.

The upper portion of the body I is counterbored at I3 to a diameter greater than the diameter of chamber |4 in the central portion of the body, to provide a shoulder I5. A head member I8 slides with a close fit into the bore I3 and is held tightly against shoulder |5 by coupling 2. 'I'he head member I8 is provided with a liquid passage establishing communication between the interior of the tubing string 3 and the interior I4 of the body. Body I is further provided with a passage I8, in the form of an aperture in the body wall, establishing communication between the zone 1 in the casing and the interior chamber I4 of the body.

The lower portion of the body is bored at I9 to a diameter which issomewhat greater than the diameter of the central bore I4 and is threaded at its upper end in order to receive valve block 2| which closes chamber |4 at its lower end. Block 2| is provided with substantially vertically extending passages 22 and 28 which both open at their lower ends to bore I8 and the space within the casing below the packing means. Passage 22 opens at its upper end to chamber I4, and has valve seat 23 at its upper end on which a ball check 24 is adapted to rest to close this passage. A suitable ball cage 25 is provided for preventing undue travel of the ball when it is lifted from its seat as will be described subsequently.

It will `be seen from the drawings that the three passages I1, I4 and 22 combine to form a continuous main passage establishing liquid communication between tubing 3 and the casing space below the packing means, since bore I9 is open at all times to this lower casing space and is in effect a part thereof. With the addition of passage I8, the above passage also communicates with zone 1. Valve means, in the form of ball 24 and its seat, are -in this combined passage to open and close the passage and regulate liquid flow therein.

Passage 28 is conically ared at its upper end at 21 to receive the lower end of the substantiallyl vertically extending conduit 28 in substantially iluid tight engagement. Conduit 28 is threaded at its upper end at 28 into the head member I8 and is provided at its upper end with a suitable valve seat 3| for reception of a ball check 32 ,which is adapted to shut oil'. uid communication downward through conduit 28 when the check is on the valve seat.

'I'he head member I8 is provided with a valve chamber 33 of suillcient size to allow necessary movement of the ball check 32 to open the passage, and suitable means, such as one or more pins 34, may be provided'for retaining the ball in the chamber. Chamber 33 opens at one side to an annular recess, (see Fig. 3) which is in fluid communication with the interior of the casing above upper packer 4 through passage 38 in the wall of the body Conduit 28 Vlies within chamber I4 and the ilrst main liquid passage described. Conduit 28, with valve chamber 33 and port 38 at its upper end and passage 28 at' its lower end, forms a second liquid passage through body This second passage is a by-pass establishing liquid communication with the casing spaces above and below the packing means. Valve means, in the form of ball 32 and its seat 3|, are in the bypass passage to open and close the passage and regulate liquid :dow therethrough.

Upon downward movement of the tool through the casing, the excess of fluid pressure from below forces ball check 32 from its seat so that i liquid in the well may by-pass the tool by flowing from the spaceV in the casing below lower packer 5 upwardly through the lower bore I8, tube 28, and passage 38 to the space in the casing above upper packer 4. lThe ball 24 can also rise and permit upward flow in passage 22, but it may or may not leave its seat 23 depending upon whether the pressure acting upwardly cn the check in passage 22 is greater than the pressure acting downwardly on the cheek from chamber I4.

It will-be seen that if an eort is made to move the tool upwardly in the casing, the fluid iiow through by-pass tube 28 is reversed and the check 32 is moved by liquid pressure against seat 3| to close the passage and no by-passing action is obtained. i Also, check 24 seals against its seat 23 to close the passage 22 and prevent kdrainage of the tubing string 3. It is extremely important that the tubing string be drained las the tool is lifted from the hole, since draining the string eliminates lifting a large vquantity oi liquid-and breaking down a tubing string full o! liquid. Therefore, there are provided means which are controllable from the surface of the ground for opening Passages 22 and 28 so that the toolmay be moved upwardly in the casing while liquids by-pass past the packers and drain from lthe tubing string. Such means is preferably controlled by relative movement of the tubing string and casing and more preferably controlled by upward movement of the tubing string with respect to the casing.

As one example of valve-operating means which I may employ, I provide push rods 38 and 39 extending respectively into the passages 22 and 28 and'adapted upon upward movement to engage and lift ball checks 24'and 32 from their respective seats to open their associated passages. The push rods are also movable to a lowered position in whichy they are outof contact with the checks to allow them to operate in accordance with the hydraulic forces imposedl thereon.

Referring to Figs. l, 2 and'4, the push rods 38 and 38 extend upwardly through guide 40, and are connected at their lower ends to cross head 4| which rides on eccentric cam 43, the cross head being a follower for the cam. Cam 43 is rotatably mounted on shaft 44 which is a bolt mounted in yoke 45 at the lower end of depending support 48 carried by the valve block 2|. A

lever arm 41 is secured to cam 43 and rotatably mountedon the shaft 44 in order to rotate the cam and is adapted for movement to a raised position as indicated in Fig. 1 in which the push rods are moved to their lower positions, out of contact with the ball checks. When lever 41 is in the lowered position, as indicated in Fig. 2, the push rods are raised to lift the bali checks from their seats and open the valves. Pin 41a in the end of lever 41 prevents the leverfrom accidentally falling inwardly through slot 49, and it is removable to permit -disassembly of the tool. Of course, any other suitable type ofvalve-operating means may be used, such as an eccentric and strap or a lever directly lifting the cross head.

In order to actuate the valve-operating means described, the arm 41 passes through a vertically extending slot 48 in the lower portion of body I and a relatively short slot 49 in sleeve 5I which is mounted for limited vertical sliding movement on the exterior of body I. Sleeve 5I is provided with suitable means for frictionally engaging the interior of the casing, such as a plurality of vertically extending bowsprings 52.

Springs 52 are secured at their upper ends to ring 53 which is fixed on the sleeve, and are secured at their lower ends to ring 54 which is slidably mounted-on the sleeve. Nut 56 is threaded onto the end of body I to limit normal downward travel of the sleeve on the body.

With the foregoing description of the construction of a preferred embodiment of my invention in mind, its operation will new be described. When the tool is lowered down inside the casing of an oil well, the frictional engagement of -bow springs 52 with the in. .er face of the casing 6 resists movement of the bow springs with respect to the casing. This frictional drag causes sleeve 5I to slide upwardly on the tool body until further motion is stopped by engagement of ring 53 with nut II, as shown in Fig. l. Movement of sleeve 5I upwardly on the body actuates the valve-operating mechanism by raising lever 41 to its uppermost position, occupied in Fig. 1. At

this time, push rods 38 Aand 39 are lowered and check valves 24-and 32 rest on their seats. At some 'point in its descent within the casing the tool encounters liquid in the Well. This liquid in the space below lower packer 5 creates a pressure on the underside of valves 2d and 32 which is in excess of the pressure onthe upper side of lthese valves, assuming that tube 3 is not full of liquid. The excess of pressure lifts either or both of the check valves off their seats and causes the well liquid either to by-pass the tool by going into 4by-pass conduit 28 and out port 36, thus reaching the casing space above packer 4, or to fill 'the tool and rise Within the'interior of tubing inem during descent of a. m01 in the casing.- the valves automatically close during cement opera# vbow springs 52 again resist movement relative to casing 6 because of the frictional engagement of the springs with the casing. Consequently, during the initial upward movement of the tool, sleeve 5I remains stationary while the'tool moves upwardly with respect to the casing and the sleeve until the bottom of the sleeve engages nut 56 which lifts the sleeve with the casing. The relative upward movement of the tool with respect to the sleeve and casing moves lever 41 of the valve-operating means to the lowered position shown in Fig. 2. Movement of this lever rotates eccentric 43 to lift c'ross head 4I and push rods 38 and 39 upwardly. The push rods engage balls 24 and 32, lifting them from their seats to open the fluid passages through the tool. Liquid communication is now reestablished between the casing spaces above and below the packing means and between the tubing and tool chamber I4 and the casing space below the packing means. As the tool is moved up within the casing, liquid in the casing above the tool can by-pass downwardly through the tool, while liquid in the tubing can drain into the space below the tool. By provision of mechanical valve-operating means which is actuated by upward movement of the body relative to the casing, the check valves are positively opened against any excess liquid pressure tending to close them, and they remain open during the ascent of the tool in the casing to permit free passage of liquid back-'into the lower portion of the well.

A modied form of the invention is disclosed f in Fig. 5. This form of the invention operates in the same manner as described and differs in construction from lthe form shown in Figs. l to 4 only in the construction and arrangement of the valve means, and the liquid passages in the valve block. In general, the two main liquid passages through the tool are joined for a portion of their length within the valve block 3. Ordinarily liquid would ll both spaces, but

by maintaining a sufficient column of liquid in the tubing, an excess of pressure may be maintained on the valve 24 to keep thevalve closed.

During cementing, testing, or flushing operations, which are described later, fluid pressure is applied to the upperside of either vor both of the check valves. Because of the construction of these check valves, they are responsive to u'id pressure diierentials and when the excess pressure is in chamber I4 or 33, it is in a direction to moveI the associated valve toward its seat and the valve under pressure closes the associated passage through the tool. Consequently, although the valves automatically open in response to excess fluid pressure from below the tool tending to open so that a single opening in the block is common to both passages, thus making it possible for one valve to control liquid flow in-both passages. More particularly, valve block 2i of Fig. l is replaced by valve block 6I which has a single vertically extending liquid passage 62 opening at its lower end 62a into bore I9 and the well space below the packing means. 'I'his vertical liquid passage It2 is provided at its upper end with a conical valve seat 63 with which cooperates a poppet type check valve 64 to control liquid flow through the passage. Passage 62 has a horizontal branch which communicates with -by-pass conduit 28. Branch passage 65 is so located with respect to valve 64 .thatliquid ow through passage 65 is stopped when valve '64 is closed.

From this construction it will be seen that'l the main liquid passage through the tool affording communication between tubing 3 by way of chamber I 4 with the casing space below the packing means, and also the by-pass passage 28, both open to bore I9 through the lower end 62a of the same passage in valve -block 6 I. However, valve 64 is respcnsive'to fluid pressure in the same manner as thebail check valves delower end of the vvalve stem 08 when the arm 41 is in its raised position and is adapted to engage the lower Aend of the valve stem to raise the valve 84 Afrom its seat when the arm 41 is in its lowered position. Push rod 38 carries a plate 38a that spans the distance between the legs of fork 45 and prevents the rod from turning and moving cross head 41| oil cam 43.

It is preferable that the valve-operating mechanism be actuated by upward movement of the tool with respect to the casing although it will be. understood that the mechanism may be modiiied to operate upon relative rotation of the tool with respect to the casing. It will also be seen that in the form of the invention illustrated in Fig. 1, both of the check valves may be located at the same level and on the valve block 2|, instead of at different levels as shown. The ex`- act type and location of the valves are not limited to those shown.

The tool may be used to locate leaks in the casing by attaching it to the tubing string and running it down the casing to `various possible locations of leaks. The excess iiuid pressure below the tool reaches the valves through the passages 22 and 26, and raises the check valves to allow liquid to l1oy-pass around the packers and also to ow into bore I4. At any desired level liquid may be. pumped down the tubing string 3 causing the check 24 tov seat and close the passage 22. If there is no leak, no liquid will escape, and the pressure rises until the pump stalls. The tool is then run on down the hole.

to another position, and the procedure repeated until a location is found at which the pump continues to operate. 'I'his indicates that the packers are on opposite sides of a leak or other opening in the casing, since liquid Vfrom the tubassumo and`ciaimed in my copending application Serial NO. 395,370, med May 27, 1941.

After the flushing operation the pump may be disconnected and the tubing string hoisted upwardly to bring the tool from the hole. Upon upward movement the arm 41 is moved to its lowered position raising the checks 24 and 32 to 5 open the passages 22 and 26, respectively. Liquid in the tubing string is thus drained through the passage 22 and suitable by-pass is provided by the passage 28.

'I claim:

1. A tool for use in combination with a well casing and a string of' tubing adapted to be moved within the casing, comprising: a vertically elongated body adapted for connection at its upper end to the tubing string; vertically spaced packf ing means carried by said body and adapted to seal off therebetween a localized zone within the casing; said body having a first passage therethrough opening outwardly of the body into the space in the casing below thepacking means for establishing liquid communication between the tubing string and said space; said body also having means defining a second passage opening o utwardly of the body into the spaces in the casing above and below the packing means; valve means ing string passes out oi' passage I4 through the passage I8 into lthe zone 1, and then out through the casing into the formation.

The leak may be cemented .by pumping cement down the tubing string and out through the passage I8 into the hole in the casing. It is preferable that the passage I8 be located closely adjacent block 2| and the lower packing cup 5 so that there is little tendency for cement to accumulate in and around the tool.

'I'he excess cement may be flushed out of the I casing and the tool by forcing liquid down the casing and discharging it from the upper end of the tubing string 3. The application of iiuid pressure from above to start this reverse circulation seats the check valve 32 to close the -by-pass passage and collapses the upper packer 4 sufficiently to pass liquid, since it faces downwardly. The lower packer 5 maintains its sealing engagement with the casing since the fluid pressure from above tends to seal it with the casing. Thus, the liquid flows down the casing past the upper packer and into lthe zone 1 iiushing the cement out of this zone and discharging it through the passage |8 into passage I4 of the tool, and out through the tubing string 3.

for opening and closing saidV passages, said first passage communicating with said zone at a position above the valve means in the iirst passage; and valve-operating'means carried by said body in position for operative engagement with said valve means and actuated by movement of the body relative to the casing to open said valve means.

2. A tool for use in combination with a well casing and a string of tubing adapted to be moved within the casing, comprising: a vertically elongated body adapted for connection at its upper end to the tubing string; verticallyspaced packing means carried by said body and adapted to seal oil! therebetween a localized zone within the casing; said body having a first passage therethrough opening outwardly of the body into the space in the casing below the packing means for establishing liquid' communication between the tubing string and said space; said body also having means defining a second passage opening outwardly of the body into the spaces in the casing above and below the packing means; separate valve means in each of said passages for opening and closing the associated passage; said rst passage communicating with said zone ai; a position above the valve means in the first passage; the

`valve means in the second passage being operable to open said second passage in response to fluid pressure in said space in the casing below the packing means; and valve-operating means carried by said body in position for operative engagement with said valve means and actuated by movement of the body relative to the casing to open said valve means.

3. In a tool for use in combination with a well casing and a string of tubing adapted to be moved within the casing, the combination which comprises: a vertically elongated body adapted for connection at its upper end to the tubing string; vertically spaced packing means carried by said body and adapted to seal oli a localized zone around the body and inside the casing; means for by-passing liquid through the body and past said packing means to allow vertical movement of the tool in the casing; a passage in said body openv ing outwardly of said body into the space in the .casing communication between the tubing string and said space and also communicating with the exterior of the body in said zone; valve means operable to open and close said passage, and located in the passage below the point of communication with the exterior of the body in said zone; means f slidably mounted on said body for limited vertical movement and adapted to frictionally engage the walls of the casing; and valve-operating means operatively connected with said slidably mounted means actuated thereby on upwardl movement of said body with respect to said slidably mounted means, to open said valve means.

4. In a tool for use in combination with a well casing and a string of tubing adapted to be moved Y within thecasing, the combination which comprises: a vertically elongated body adapted for connection at its upper end to the tubing string; vertically spaced packing means carried by said body and adapted to seal oi a localized zone around the body and inside the casing; a passage in the body opening outwardly of the body into the space in the casing below said packing means for establishing communication between the tubing string and said space and also communicating with vthe exterior of the body in said zone; means providing a by-pass passage in the body for by-passing liquid through the body and past the packing means to allow vertical movement of the tool in the casing; valve means in the bypass passage operable to open and close the bypass; means slidably mounted on said body for limited vertical movement and adapted` to frictionally engage the walls of the casing; and valveoperating means operatively connected with said slidably mounted means and actuated thereby on upward movement of said body with respect to said slidably mounted means to open said Valve means. Y

5. A tool for use in combination with a well within the casing, comprising: a verelongated body adapted for connection upper end to the tubing string; verspaced packing means carried by said moved tically at its tically body and adapted to seal ofi therebetween a localized zone within the casing; said body having a first passage therethrough opening outwardly of the body into the space in the casing below the packing means for establishing liquid communication between the tubing string and said space, and having a second passage opening outwardly of the body into the spaces in the casing above and below said packing-means; separate valve means in each of said passages for opening and closing the associated passage, the valve means inthe second passage being operable to open said secondpassage in response to liquid pressure in said space in the casing below the packing means; said iirst passage communicating with said zone at a position above the valve means in the rst passage; and valve operating means carried by said body in position for operative engagement with said valve means and actuated by upward movement of the body relative to the casing to open said valve means.

6. In a tool for use in connection with a. well casing and a string of tubing adapted to be moved within the casing, the combination which comprises: a vertically elongated body adapted for connection at its upper end to the tubing string; vertically spaced packing means carried by said body and adapted to seal 01T a localized zone around the body and inside the casing; means for by-passing liquid through the body and past said packing means to allow vertical movement of the tool in the casing; a passage in said body opening outwardly 'of said body into the space in the casing below said packing means. for establishing communication between the tubing string. and said space and also communicating with the exterior of the body in said zone;

-valve means operable to open and close said passage, and located in the passage below the point of communication'with the exterior of the body in said zone; and valve operating means carried by said body inposition for operative engagement with said valve means and actuated by upward movement of the body relative to the casing to open said valve means.

, 7. In a tool for use in combination with a well casing Aand a string of tubing adapted to be moved within the casing, said tool having a body, vertically spaced packers adapted to seal off a zone inside the casing and around thebody, and a chamber in the body communicating with the tubing string and the zone between the packers.

the combination which comprises: means in the body defining a by-pass passage opening outwardlyof the body-into the spaces in the casing above and below the packers and defining a second passage opening outwardly of the chamber into said space in the casing below the packers; a

- check valve in each of said passages for controlling liquid flow through the passages, the check mit movement of liquid through the passages as the tool descends in the casing; andv Valve operand a string of tubing adapted to be ating means carried by said body in position for operative engagement with said check valves and Vactuated by upward movement of the body relative to the casing to positively open said check valves and thereby permit flow of liquid through the passages as the tool ascends in the casing.

8. In a tooll for use in combination with a vwell casing and -a string'of tubing adapted to be liliv moved within the casing, said tool having a body, vertically spaced packers yadapted to seal off a zone inside the casing and around the body, ,and a chamber in the body communicating with the tubing string and the zone .between the packers, the combination which comprises: means in the body defining a passage outwardly of the body into the space in the casing below the packers and leading from the chamberfto said space; valve means in said passage operable to open and close -said passage; and valve operating means carried by said body in position for operative engagement with said valve means land actuated by upward movement of the body relative to the casing to open said valve means.

9. In a tool for use in combination with a well casing and la string of tubing adapted to be moved within the casing, said tool having a body, vertically spaced packers adapted to seal off a zone inside the casing and around the body, and a chamber in the body communicating with the tubing string and the zone between the packers, the combination which comprises: means in the body deiining a passage opening outwardly of the body into the space in the casing below the packers and leading from the chamber to said space; a fluid pressure operable check valve in said passage adapted to be opened by the fluid pressure in said space when such pressure exceeds the chamber pressure and to be closed when such pressure isless than the chamber pressure; means slidably mounted on the tool body and frictionally engaging the casing to resist movement relative thereto: and valve-operating means carried by said body in position for operative engagement with said check valve and said slidably mounted means and actuated by upward movement of the body relative to the slidably mounted means to positivelyY open the check valve.

10. In a tool for use in combination with a well casing and a string of tubing adapted to be moved within the casing, said tool having a body, vertically spaced packers adapted to'seal oil.' a zone inside the casing and around the body, and a chamber in the body communicating with the tubing string andthe zone between the packers, the combination which comprises: means in the body defining a by-pass passage opening outwardly of the body into the spaces in the casing above and below the packers; valve means in said passage operable to open and close said passage; and valve-operating means carried by said body body defining a by-pass passage opening out;

wardly of the body into the spaces in the casing above and below the packers; a iluid pressure operable check valve in said passage adapted to be opened by the iluid pressure in the casing in said space below the packers when such pressure exceeds the chamber pressure and closed in position for operative engagement with said s valve means and actuated by upward movement oi' the body relative to the casing to open said valve means.

11. In a tool for use in combination with a well when such pressure is less than the chamber pressure; means slidably mounted on the tool body and frictionaily engaging the casing to resist movement relative thereto; and valve-operating means carried by said body in position for operative engagement with said check valve and said slidably mounted means andactuated by upward movement of the body relative to the slidably mounted means to positively open the check Valve.

i PAUL H. GRAN GER. 

